DESCRIPTION: Although significant progress has been made in the development of an HIV-1 vaccine, we are just now beginning to make progress toward the induction of mucosal immunity. A major limitation on the development of mucosal vaccines has been difficulty in quantitatively evaluating the immune response at mucosal surfaces. We propose to develop an assay which will provide a quantitative measure of epitope specific antibodies at the mucosa. It is our hypothesis that the induction of mucosal antibodies can be accurately measured using this method and that the information will lead to improved HIV-1 vaccines that will block the spread of infection. Our proposed Quantitative Epitope Mapping ELISA format, or QEM ELISA, provides a sensitive way of measuring the concentration of epitope specific antibody. The assay can be easily adapted to analysis of samples with widely varying levels of antibody including serum, saliva, feces, and urine with minor modifications of the assay format. The assay can also be used to measure isotype specific epitopes without the need to deplete the sample for competing Ig subclasses or other interfering substances. Long term the QEM ELISA will have broad application to the analysis of vaccines for other disease (e.g. rotavirus, RSV, influenza, H. pylori, HPV, etc.). PROPOSED COMMERCIAL APPLICATION: Not available.